Firstly, welcome to the forums.
1. Cottages. when i build one it says city needs to work te become a hamlet. So how do i get the city to work?
A city 'works' an improvement when its citizens are utilising that tile. So, in the city screen, there will be several tiles with circles around them. Those are the tiles that are being 'worked', and the bonuses from each tile will contribute to the city's production, food and commerce. So, in order to grow a cottage to become a hamlet (which increases its commerce output), your citizens need to 'work' the tile with the cottage for a certain number of turns, at which point it automatically upgrades, and its yield automatically increases.
2. The only victories i could get so far were cultural, when i have some agressive neighbours they just declare on me when im not expecting it and rape me... How do I prevent this? In other words how to build a decent military while still focussing on economy??
That can be tough. The best way of doing this is to conduct sustainable warfare throughout the duration of the game, instead of simply bottling up. You need to be reasonably strong in order to be able to afford to sit on the back foot for a cultural victory. If you eliminate your opponents, or damage their power early on, then they will not pose as big a threat to you in the late game. Additionally, if you are going for a cultural victory, you can get to a certain point in the game (perhaps Rifling), where you turn off the research slider, and use the resultant gold to power the cultural slider, and pay for a powerful army, produced by those cities other than the three required for cultural victory. So, if you can do this, you shouldn't have all that much problem pumping out units from your non-culture cities in order to deter/repel any attack.
3. Some tips on outteching the opponent? I know trading helps but...
Out teching the AI can be hard. Trade certainly helps, and can be exploited to a certain extent. But having a powerful economy is very important, too. This allows for continued research. One of my personal preferences is to go for Industrialism early, build up your industry, becoming a productive powerhouse, which will in turn assist with research (either through buildings multiplying research, or through actually building research). And if that fails, there is always getting techs out of civs through war.
Hope that helped.
